The present invention relates to manifold valves and pressure transducers in fluid communication with main fluid pressure lines, and more particularly to assemblies of manifold valves and pressure transducers for outputting signals representing pressures in two pressurized fluid lines.
Manifold valves are known in the art. Manifold valves typically are mounted between the main fluid pressure lines and the pressure transducers. Manifold valves permit isolating the pressure lines from the pressure transducers in order to facilitate their removal or replacement and are required for calibration purposes. The manifold valve of the present invention includes a first inlet port and a second inlet port with internal passageways that run past isolation valves to a first outlet port and second outlet port that are connected to corresponding inlet ports on the pressure transducers.
Differential pressure transmitters are known in the art. Manifold valves are used in conjunction with differential pressure transmitters. The manifold valve in the present invention has an integral flange that mates with differential pressure transmitters as in U.S. Pat. No. 6,279,401 B1, incorporated herein by reference in its entirety. The flange connection is standard in the industry and is used to directly mount a manifold valve to a differential pressure transmitter without the use of piping components. Differential pressure transmitters of this type include pressure-sensing components, which include pressure transducers, with signal processing circuits and are typically manufactured as a complete unit. The signal processing circuit of the differential pressure transmitters combines the low-pressure and high-pressure output signals of the pressure sensors into a single output signal that is indicative of the pressure difference. The costs of these types of transmitters typically are higher than the cost of the manifold valve.
Fully integrated manifold valves and differential pressure transmitters also are known in the art. They typically combine a manifold valve and differential pressure transmitter into a single manufactured unit. U.S. Pat. No. 4,865,360, incorporated herein by reference in its entirety, relates to this type of fully integrated assembly. The time required to assemble these units into fluid pipelines is significantly lower than assembling separate manifold and pressure transducers, but the costs of these units also are higher.
Pressure transducers, manifold valves and signal processing circuits can be purchased on a stand-alone basis and assembled using standard piping components. The costs of the individual components are relatively low, but the costs associated with assembling them into fluid pipelines are significantly higher than integrated units. An optimal manifold valve and differential pressure transmitter assembly would use low cost standard components that can be assembled rapidly using a minimal amount of piping components. Known manifold valve and differential pressure transmitter assemblies have attempted to accomplish this. U.S. Pat. No. 6,349,735 B2, incorporated herein by reference in its entirety, relates to an example of this type of assembly. This assembly, however, still makes use of piping components, and although the manifold valve is modular, the pressure transducers are not.
Further, U.S. Pat. No. 4,466,290, incorporated herein by reference in its entirety, relates to a differential pressure transmitter attached to a three valve manifold employing a standard mounting flange used in the industry and incorporated between a three valve manifold and a single transmitter.
Further improvements are needed that make use of standard low cost, interchangeable components that can be quickly assembled with the same functionality as their more expensive counterparts.